1. Field of the Invention
The present invention relates to a variable grip locking plier for gripping a workpiece, and more particularly, the present invention relates to a self-adjusting variable grip locking plier for gripping a workpiece.
2. Description of the Prior Art
Numerous other innovations for pliers have been provided in the prior art that will be described. Even though these innovations may be suitable for the specific individual purposes to which they address, however, they differ from the present invention.
A FIRST EXAMPLE, U.S. Pat. No. 3,379,079 to Cutter teaches a clamping apparatus comprising, in combination: first and second actuating arms; means connecting said arms together for rotating one end of each of said arms about a common axis for movement of the other ends of said arms in directions toward and away from each other; work engaging means secured on the other end of each of said arms; means mounted intermediate the ends of said arms for locking said arms relative to each other, said locking means including a toggle joint movable from an unlocked position to a locked position for forcing said arms toward one another, said arms being retained proximate each other when the toggle joint is in the locked position; said toggle joint having two end pivot pins and at least one intermediate pivot pin, and means providing equal movement of said end pivot pins relative to each other when said toggle joint is in the locked position and said arms are moved together and away from one another whereby said work engaging means will maintain the same force on any size workpiece held therein.
A SECOND EXAMPLE, U.S. Pat. No. 3,672,245 to Hoffman teaches pliers for positively gripping a selected work piece between substantially parallel gripping jaw surfaces, one of which is carried by a fixed handle, the other of which is carried by a pivoted toggle member mounted on an extension of the fixed handle for pivotal movement and adjustment toward and away from the jaw on the fixed handle, a handle pivotally connected to the toggle member and tensioning means connecting said handles and adjustment means on the fixed handle and having pivotal connection with the pivoted handle whereby the gripping effort on a selected work piece may be adjusted to secure a strong positive grip thereon without causing damage to the work piece.
A THIRD EXAMPLE, U.S. Pat. No. 5,022,290 to Duffy teaches a locking plier-wrench including a first handle member having a first jaw member lockable at a plurality of positions relative to the handle member and removable from the handle member so that a different jaw member having a different length shank may be substituted, and a second jaw member pivotally mounted on the handle member and straddling the handle member.
A FOURTH EXAMPLE, U.S. Pat. No. 5,609,080 to Flavigny teaches locking pliers including a fixed unit of generally elongate shape which forms at one end a fixed handle and at the other end a fixed jaw. A movable unit includes a movable jaw articulated to the fixed jaw, and an actuating lever of which one end is articulated to the movable jaw and the other end forms a movable handle. Also, a toggle mechanism is provided and includes a link articulated to an intermediate point of the lever and extending to a rear bearing point adjustable along the length of the fixed handle. The actuating lever crosses a straight line which joins the articulation of the movable jaw to the bearing point of the link, and the fixed handle extends substantially along a straight line joining the articulation to the bearing point.
A FIFTH EXAMPLE, U.S. Pat. No. 6,279,431 to Seber, et al. teaches a self-adjusting pliers that is operable to grasp a workpiece between an upper jaw and a lower jaw. The pliers includes an upper arm having the upper jaw and a lower arm, with the lower jaw linked to the lower arm but not integral with the lower arm. A control arm has a first end and a second end. The first end of the control arm has a first pivotable connection to the upper arm adjacent to an end of the upper arm remote from the upper jaw, and the second end of the control arm has a second pivotable connection to the lower arm at an intermediate location along the length of the lower arm. An upper control arm pivot pin provides the pivotable connection between the first end of the control arm and the upper arm, and a spring biases the control arm so as to resist rotation of the control arm about the upper control arm pivot pin. A support extends downwardly from the upper arm toward the lower arm and has a guide thereon. The lower jaw slidably engages the guide such that the lower jaw is constrained to follow the guide when the lower arm is pivoted about the upper control arm pivot pin.
A SIXTH EXAMPLE, U.S. Pat. No. 6,578,452 to Duffy teaches a vise grip locking tool which contains jaws that are capable of opening with a flick of the user's wrist. The tool comprises a first handle member, a second handle member, a lower jaw, and an upper jaw. The first handle member is pivotally attached to the lower jaw. The first end of the lower jaw is made up of four mutually interconnected sides having a guided slot extending through it. The upper jaw has an elongated shank that may slide along the guided slot of the lower jaw. A stop is present on the bottom of the shank preventing the upper jaw from escaping the guided slot. The second handle member is pivotally mounted to the lower jaw and includes a releasable lock which is made up of a spring-operated detent which engages teeth on the elongated shank.
A SEVENTH EXAMPLE, U.S. Pat. No. 6,748,829 to Seber, et al. teaches a self-adjusting pliers that is operable to grasp a workpiece between an upper jaw and a lower jaw. The pliers includes an upper arm having the upper jaw and a lower arm, with the lower jaw linked to the lower arm but not integral with the lower arm. A control arm has a first end and a second end. The first end of the control arm has a first pivotable connection to the upper arm adjacent to an end of the upper arm remote from the upper jaw, and the second end of the control arm has a second pivotable connection to the lower arm at an intermediate location along the length of the lower arm. An upper control arm pivot pin provides the pivotable connection between the first end of the control arm and the upper arm, and a spring biases the control arm so as to resist rotation of the control arm about the upper control arm pivot pin. A support extends downwardly from the upper arm toward the lower arm and has a guide thereon. The lower jaw slidably engages the guide such that the lower jaw is constrained to follow the guide when the lower arm is pivoted about the upper control arm pivot pin.
It is apparent that numerous innovations for pliers have been provided in the prior art that are adapted to be used. Furthermore, even though these innovations may be suitable for the specific individual purposes to which they address, however, they would not be suitable for the purposes of the present invention as heretofore described.